Plugged Honeycomb Structure Pore Distribution for Pressure Loss Stability

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Solution Overview

Problem

Conventional plugged honeycomb structures exhibit significant variations in pressure loss when loaded with catalyst, affecting the efficiency and stability of exhaust gas purification and engine control processing due to their sharp peak-shaped pore diameter distribution.

Innovation Solution

A plugged honeycomb structure with a pore diameter distribution that is closer to a rectangle shape, characterized by specific ratios of cumulative pore volumes (D10, D30, D50, D70, D90) and porosity, which minimizes variations in pressure loss even with changes in catalyst particle diameter or loading conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the pore diameter distribution is made sharp peak-shaped to improve trapping efficiency and reduce pressure loss, then the trapping performance is improved, but the pressure loss variation increases significantly when catalyst is loaded

Engineering Contradiction:

Improvetrapping efficiencyVSAvoidpressure loss variation

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention changes the pore diameter distribution parameters from a sharp peak shape to a flat-top shape with specific D10, D30, D50, D70, and D90 values. This parameter modification allows the filter to maintain low pressure loss while reducing pressure loss variation after catalyst loading, thereby resolving the contradiction between trapping efficiency and reliability.

Inventive Principle:

Principle #35Parameter changes

2Stress or pressure

If the pore diameter distribution is made sharp peak-shaped to reduce pressure loss, then the pressure loss is reduced, but the pressure loss stability deteriorates after catalyst loading

Engineering Contradiction:

Improvepressure lossVSAvoidpressure loss stability

Core Design Contradiction:

Stress or pressureVSStability of the object's composition

Solution Approach 1:

The invention modifies the pore diameter distribution parameters to create a flat-top shape with specific D10, D30, D50, D70, and D90 values. This parameter change enables the filter to maintain low pressure loss while achieving stable pressure loss characteristics after catalyst loading, resolving the contradiction between pressure loss reduction and stability.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the pore diameter distribution is made sharp peak-shaped to improve trapping performance, then the trapping performance is improved, but the variation in pressure loss after catalyst loading increases

Engineering Contradiction:

Improvetrapping performanceVSAvoidpressure loss consistency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the pore diameter distribution parameters from a sharp peak shape to a flat-top shape with specific D10, D30, D50, D70, and D90 values. This parameter modification ensures consistent pressure loss characteristics across different catalyst batches and loading conditions while maintaining high trapping performance, thereby resolving the contradiction between reliability and manufacturing precision.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration ensures stable exhaust systems and precise engine control by maintaining low pressure loss variations, enhancing the trapping performance and durability of the plugged honeycomb structure.

Implementation Method 1

The porous partition walls of this plugged honeycomb structure serves as a filter to trap particulate matters in exhaust gas

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

the catalyst is for removing a toxic gas component from exhaust gas for purification. The thus configured plugged honeycomb structure can purify the exhaust gas during the passage through the partition walls by removing toxic gas components from the exhaust gas with the catalyst loaded in the pores

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS11167279B2Plugged honeycomb structure

Publication Date: 2021.11.09 NGK INSULATORS LTD

AI summary

A plugged honeycomb structure, including: a pillar-shaped honeycomb structure body including porous partition walls; and plugging portions disposed at open ends of cells at an inflow end face side or at an outflow end face side, wherein a pore diameter corresponding to the cumulative pore volume of 10% is D10, a pore diameter corresponding to the cumulative pore volume of 30% is D30, a pore diameter corresponding to the cumulative pore volume of 50% is D50, a pore diameter corresponding to the cumulative pore volume of 70% is D70, a pore diameter corresponding to the cumulative pore volume of 90% is D90, the pore diameter D10 is 6 μm or more, the pore diameter D90 is 58 μm or less, and the plugged honeycomb structure satisfies the relationship of Expression (1).0.35≤(D70−D30)/D50≤1.5 Expression (1):